python - 使用 python 和 nodejs 加密和解密

Question

我正在尝试在 Python 中加密某些内容并在 nodejs 应用程序中对其进行解密。

不过，我正在努力让这两个 AES 实现协同工作。这就是我所在的位置。

在 Node 中:

var crypto = require('crypto');

var password = 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa';
var input = 'hello world';

var encrypt = function (input, password, callback) {
    var m = crypto.createHash('md5');
    m.update(password)
    var key = m.digest('hex');

    m = crypto.createHash('md5');
    m.update(password + key)
    var iv = m.digest('hex');

    // add padding
    while (input.length % 16 !== 0) {
        input += ' ';
    }

    var data = new Buffer(input, 'utf8').toString('binary');

    var cipher = crypto.createCipheriv('aes-256-cbc', key, iv.slice(0,16));
    var encrypted = cipher.update(data, 'binary') + cipher.final('binary');
    var encoded = new Buffer(encrypted, 'binary').toString('base64');

    callback(encoded);
};

var decrypt = function (input, password, callback) {
    // Convert urlsafe base64 to normal base64
    var input = input.replace('-', '+').replace('/', '_');
    // Convert from base64 to binary string
    var edata = new Buffer(input, 'base64').toString('binary')

    // Create key from password
    var m = crypto.createHash('md5');
    m.update(password)
    var key = m.digest('hex');

    // Create iv from password and key
    m = crypto.createHash('md5');
    m.update(password + key)
    var iv = m.digest('hex');

    // Decipher encrypted data
    var decipher = crypto.createDecipheriv('aes-256-cbc', key, iv.slice(0,16));
    var decrypted = decipher.update(edata, 'binary') + decipher.final('binary');
    var plaintext = new Buffer(decrypted, 'binary').toString('utf8');

    callback(plaintext);
};

encrypt(input, password, function (encoded) {
    console.log(encoded);
    decrypt(encoded, password, function (output) {
        console.log(output);
    });
});

这会产生输出:

BXSGjDAYKeXlaRXVVJGuREKTPiiXeam8W9e96Nknt3E=
hello world 

在python中

from Crypto.Cipher import AES
from hashlib import md5
import base64

password = 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'
input = 'hello world'

def _encrypt(data, nonce, password):
    m = md5()
    m.update(password)
    key = m.hexdigest()

    m = md5()
    m.update(password + key)
    iv = m.hexdigest()

    # pad to 16 bytes
    data = data + " " * (16 - len(data) % 16)

    aes = AES.new(key, AES.MODE_CBC, iv[:16])

    encrypted = aes.encrypt(data)
    return base64.urlsafe_b64encode(encrypted)

def _decrypt(edata, nonce, password):
    edata = base64.urlsafe_b64decode(edata)

    m = md5()
    m.update(password)
    key = m.hexdigest()

    m = md5()
    m.update(password + key)
    iv = m.hexdigest()

    aes = AES.new(key, AES.MODE_CBC, iv[:16])
    return aes.decrypt(edata)

output = _encrypt(input, "", password) 
print(output)
plaintext = _decrypt(output, "", password)
print(plaintext)

这会产生输出

BXSGjDAYKeXlaRXVVJGuRA==
hello world 

显然它们非常接近，但 Node 似乎正在用一些东西填充输出。有什么想法可以让两者互操作吗？

Answer 1

好的，我想通了， Node 使用 OpenSSL，它使用 PKCS5做填充。 PyCrypto 不处理填充，所以我自己做的只是在两者中添加 ' '。

如果我在 python 代码中添加 PKCS5 填充并在 Node 代码中删除填充，它可以工作。

所以更新了工作代码。 Node :

var crypto = require('crypto');

var password = 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa';
var input = 'hello world';

var encrypt = function (input, password, callback) {
    var m = crypto.createHash('md5');
    m.update(password)
    var key = m.digest('hex');

    m = crypto.createHash('md5');
    m.update(password + key)
    var iv = m.digest('hex');

    var data = new Buffer(input, 'utf8').toString('binary');

    var cipher = crypto.createCipheriv('aes-256-cbc', key, iv.slice(0,16));
    
    // UPDATE: crypto changed in v0.10
    // https://github.com/joyent/node/wiki/Api-changes-between-v0.8-and-v0.10 
    var nodev = process.version.match(/^v(\d+)\.(\d+)/);
    var encrypted;

    if( nodev[1] === '0' && parseInt(nodev[2]) < 10) {
        encrypted = cipher.update(data, 'binary') + cipher.final('binary');
    } else {
        encrypted = cipher.update(data, 'utf8', 'binary') + cipher.final('binary');
    }

    var encoded = new Buffer(encrypted, 'binary').toString('base64');

    callback(encoded);
};

var decrypt = function (input, password, callback) {
    // Convert urlsafe base64 to normal base64
    var input = input.replace(/\-/g, '+').replace(/_/g, '/');
    // Convert from base64 to binary string
    var edata = new Buffer(input, 'base64').toString('binary')
    
    // Create key from password
    var m = crypto.createHash('md5');
    m.update(password)
    var key = m.digest('hex');

    // Create iv from password and key
    m = crypto.createHash('md5');
    m.update(password + key)
    var iv = m.digest('hex');

    // Decipher encrypted data
    var decipher = crypto.createDecipheriv('aes-256-cbc', key, iv.slice(0,16));

    // UPDATE: crypto changed in v0.10
    // https://github.com/joyent/node/wiki/Api-changes-between-v0.8-and-v0.10 
    var nodev = process.version.match(/^v(\d+)\.(\d+)/);
    var decrypted, plaintext;

    if( nodev[1] === '0' && parseInt(nodev[2]) < 10) {  
        decrypted = decipher.update(edata, 'binary') + decipher.final('binary');    
        plaintext = new Buffer(decrypted, 'binary').toString('utf8');
    } else {
        plaintext = (decipher.update(edata, 'binary', 'utf8') + decipher.final('utf8'));
    }

    callback(plaintext);
};

encrypt(input, password, function (encoded) {
    console.log(encoded);
    decrypt(encoded, password, function (output) {
        console.log(output);
    });
});

Python:

from Crypto.Cipher import AES
from hashlib import md5
import base64

password = 'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'
input = 'hello world'

BLOCK_SIZE = 16

def pad (data):
    pad = BLOCK_SIZE - len(data) % BLOCK_SIZE
    return data + pad * chr(pad)

def unpad (padded):
    pad = ord(chr(padded[-1]))
    return padded[:-pad]

def get_key_iv (password):
    m = md5()
    m.update(password.encode('utf-8'))
    key = m.hexdigest()

    m = md5()
    m.update((password + key).encode('utf-8'))
    iv = m.hexdigest()
    
    return [key,iv]

def _encrypt(data, password):

    key,iv = get_key_iv(password)
    data = pad(data)

    aes = AES.new(key, AES.MODE_CBC, iv[:16])

    encrypted = aes.encrypt(data)
    return base64.urlsafe_b64encode(encrypted)

def _decrypt(edata, password):
    edata = base64.urlsafe_b64decode(edata)
    key,iv = get_key_iv(password)

    aes = AES.new(key, AES.MODE_CBC, iv[:16])
    return unpad(aes.decrypt(edata))


output = _encrypt(input, password) 
print(output)
plaintext = _decrypt(output, password)
print(plaintext)